VOIDP Super( stack )
VOIDP stack;
Super() allows you to interrogate or alter the state of the 680x0.
Opcode
32 (0x20)
Availability
Parameters
stack defines the meaning of the call as follows:
| Name |
stack |
Meaning |
| SUP_SET |
(VOIDP)0 |
The processor is placed in supervisor mode and the old supervisor stack is returned. |
| SUP_INQUIRE |
(VOIDP)1 |
This interrogates the current mode of the processor. If the processor is in user mode a SUP_USER (0) is returned, otherwise a SUP_SUPER (1) is returned. |
| - |
>1 |
The processor is placed in user mode and the supervisor stack is reset to stack. |
Binding
pea stack
move.w #$20,-(sp)
trap #1
addq.l #6,sp
Return Value
Super() returns a different value based on the
stack parameter. The various return values are explained above.
Caveats
You should never call the
AES in supervisor mode. In addition, supervisor mode should be entered and left in the same
stack context (same 'C' function) or stack corruption can result.
Comments
To execute portion of a program in supervisor mode you normally call
Super() with a parameter of
0 and save the return value. When ready to return to user mode you call
Super() again with the saved return value as a parameter. Supervisor mode should be used sparingly under
MiNT as no task switching can occur.
See Also